| 31st Jul 2018 7:00 am | 
                                            RNS | 
                                            Mandatory Conversion: remaining Convertible Bonds | 
                                        
                                                                            
                                            | 26th Jul 2018 9:00 am | 
                                            RNS | 
                                            Additional Listing | 
                                        
                                                                            
                                            | 13th Jul 2018 5:00 pm | 
                                            RNS | 
                                            Holding(s) in Company | 
                                        
                                                                            
                                            | 12th Jul 2018 7:00 am | 
                                            RNS | 
                                            Trading and Operations Update | 
                                        
                                                                            
                                            | 4th Jul 2018 11:00 am | 
                                            RNS | 
                                            Additional Listing | 
                                        
                                                                            
                                            | 3rd Jul 2018 5:00 pm | 
                                            RNS | 
                                            Director/PDMR Shareholding | 
                                        
                                                                            
                                            | 2nd Jul 2018 10:00 am | 
                                            RNS | 
                                            Block listing Interim Review | 
                                        
                                                                            
                                            | 2nd Jul 2018 10:00 am | 
                                            RNS | 
                                            Total Voting Rights and Warrant Update | 
                                        
                                                                            
                                            | 18th Jun 2018 4:00 pm | 
                                            RNS | 
                                            Holding(s) in Company | 
                                        
                                                                            
                                            | 4th Jun 2018 5:30 pm | 
                                            RNS | 
                                            Director/PDMR Shareholding | 
                                        
                                                                            
                                            | 1st Jun 2018 10:00 am | 
                                            RNS | 
                                            Total Voting Rights and Warrant Update | 
                                        
                                                                            
                                            | 31st May 2018 7:00 am | 
                                            RNS | 
                                            Inclusion in FTSE 250 Index | 
                                        
                                                                            
                                            | 16th May 2018 6:03 pm | 
                                            RNS | 
                                            Result of AGM | 
                                        
                                                                            
                                            | 16th May 2018 7:00 am | 
                                            RNS | 
                                            Trading and Operations Update | 
                                        
                                                                            
                                            | 4th May 2018 4:30 pm | 
                                            RNS | 
                                            Director/PDMR Shareholding | 
                                        
                                                                            
                                            | 3rd May 2018 5:00 pm | 
                                            RNS | 
                                            Holding(s) in Company | 
                                        
                                                                            
                                            | 2nd May 2018 5:30 pm | 
                                            RNS | 
                                            Director/PDMR Shareholding | 
                                        
                                                                            
                                            | 1st May 2018 9:30 am | 
                                            RNS | 
                                            Total Voting Rights and Warrant Update | 
                                        
                                                                            
                                            | 30th Apr 2018 7:00 am | 
                                            RNS | 
                                            Sale of Babbage Area interests | 
                                        
                                                                            
                                            | 26th Apr 2018 9:00 am | 
                                            RNS | 
                                            Additional Listing | 
                                        
                                                                            
                                            | 9th Apr 2018 5:30 pm | 
                                            RNS | 
                                            Holding(s) in Company | 
                                        
                                                                            
                                            | 6th Apr 2018 4:45 pm | 
                                            RNS | 
                                            Annual Financial Report | 
                                        
                                                                            
                                            | 5th Apr 2018 11:00 am | 
                                            RNS | 
                                            Director/PDMR Shareholding | 
                                        
                                                                            
                                            | 3rd Apr 2018 12:15 pm | 
                                            RNS | 
                                            Total Voting Rights and Warrant Update | 
                                        
                                                                            
                                            | 28th Mar 2018 7:00 am | 
                                            RNS | 
                                            Award of three blocks in Mexico's Round 3.1 | 
                                        
                                                                            
                                            | 16th Mar 2018 5:30 pm | 
                                            RNS | 
                                            Director/PDMR Shareholding | 
                                        
                                                                            
                                            | 8th Mar 2018 7:00 am | 
                                            RNS | 
                                            Full Year Results | 
                                        
                                                                            
                                            | 2nd Mar 2018 3:00 pm | 
                                            RNS | 
                                            Director/PDMR Shareholding | 
                                        
                                                                            
                                            | 1st Mar 2018 11:00 am | 
                                            RNS | 
                                            Total Voting Rights and Warrant Update | 
                                        
                                                                            
                                            | 2nd Feb 2018 5:00 pm | 
                                            RNS | 
                                            Director/PDMR Shareholding | 
                                        
                                                                            
                                            | 1st Feb 2018 12:00 pm | 
                                            RNS | 
                                            Director/PDMR Shareholding | 
                                        
                                                                            
                                            | 1st Feb 2018 9:00 am | 
                                            RNS | 
                                            Total Voting Rights and Warrant Update | 
                                        
                                                                            
                                            | 31st Jan 2018 7:00 am | 
                                            RNS | 
                                            Award of the Andaman II licence, Indonesia | 
                                        
                                                                            
                                            | 29th Jan 2018 9:00 am | 
                                            RNS | 
                                            Holding(s) in Company | 
                                        
                                                                            
                                            | 26th Jan 2018 9:00 am | 
                                            RNS | 
                                            Additional Listing | 
                                        
                                                                            
                                            | 26th Jan 2018 9:00 am | 
                                            RNS | 
                                            Holding(s) in Company | 
                                        
                                                                            
                                            | 25th Jan 2018 11:00 am | 
                                            RNS | 
                                            Holding(s) in Company | 
                                        
                                                                            
                                            | 24th Jan 2018 3:00 pm | 
                                            RNS | 
                                            Holding(s) in Company | 
                                        
                                                                            
                                            | 24th Jan 2018 7:00 am | 
                                            RNS | 
                                            Catcher operational update | 
                                        
                                                                            
                                            | 23rd Jan 2018 11:00 am | 
                                            RNS | 
                                            Holding(s) in Company |